Typically, electronic devices include one or more camera modules for providing enhanced media functionality. For example, the typical electronic device may utilize the camera modules for photo capturing and video teleconferencing. In the typical electronic device with multiple camera modules, the primary camera module has a high pixel density and an adjustable focus lens system, while the secondary camera module is front-facing and has a lower pixel density. Also, the secondary camera module may have a fixed focus lens system.
For example, U.S. Patent Application No. 2009/0057544 to Brodie et al, assigned to the present application's assignee, discloses a camera module for a mobile device. The camera module comprises a lens, a housing carrying the lens, and a lens cap over the lens and housing. The camera module includes a barrel mechanism for adjusting the lens. During manufacture of an electronic device including one or more camera modules, there is a desire to manufacture the electronic device as quickly as possible, particularly in mass production runs. Also, given the typical mobile device application, there is a desire to reduce the size of the camera module.
One approach to reducing the size of an optical device includes using a liquid crystal cell that operates as a variable focus lens. Rather than physically moving a lens element like traditional mechanical approaches to focusing a lens, in a liquid crystal cell, a small control voltage is applied to dynamically change the refractive index of the material the light passes through. Such a liquid crystal cell is available from LensVector, Inc. of Sunnyvale, Calif.
Connecting the liquid crystal cell within an optical device, for example, within a lens housing, may be performed using an electrically conductive adhesive. More particularly, one or more pairs of opposing electrically conductive contacts may be associated with the liquid crystal cell, and the electrically conductive adhesive is used to electrically couple the electrical contacts.
U.S. Patent Application Publication No. 2011/0221950 to Oostra et al. discloses a camera device. The camera device includes an image sensor integrated circuit (IC), and a lens over the image sensor IC. The camera device also includes an electrically variable focus polymer-stabilized liquid crystal lens over the image sensor IC, and conductive glue around the variable focus polymer-stabilized liquid crystal lens.
Referring to FIGS. 1-3, an approach to an image sensor device 90 is shown. The image sensor device 90 includes a liquid crystal cell 91 comprising a plurality of cell layers 92a-92d, and a plurality of electrically conductive contacts 93a-93b carried thereby. The image sensor device 90 includes a housing 94, a plurality of electrically conductive traces 95a-95b carried by the housing, and electrically conductive paste 96 coupling the electrically conductive traces and the electrically conductive contacts. The housing 94 and the liquid crystal cell 91 define a recess 98 therebetween, and the electrically conductive paste 96 fills the recess (being dispensed by a nozzle 97 during manufacturing steps shown in FIGS. 2A-2B).